WALL ELEMENT PROVIDED WITH VENTILATION PASSAGES

Abstract: Floor element for a storage space for compost, potatoes and other products which have to be in contact with air during storage, wherein the floor element has ventilation passages (10), which run from the one side to the other side of the floor element and debouch into the side of the wall element which faces the products at a distance from the actual supporting surface. A network of mutually intersecting channels (89) which are open towards the supporting surface (5) extend between the outlets of the ventilation passages (10) which ensure an optimal feed and discharge respectively of air for ventilating the products to and from the layer of products which is resting on the supporting surface.

Description: Wall element provided with ventilation passages The invention relates to a wall element, that is to say a floor element or a vertical wall element, for storage spaces for storing goods such as compost, potatoes, car¬ rots, sugar-beet, but also seeds, grain and so forth, which during storage have to come into contact with gases (air) and/or liquids, which have to be led through the goods via wall elements. This can, for example, be to avoid anaerobic processes, to cool or to dry. Storing such goods in an open storage is known, the goods, possibly supported in a transverse direction by concrete vertical wall elements, being put on a floor which is made up of a series of floor elements forming a paving, the floor elements being provided with through slots. These slots extend from the supporting surface of the floor elements to the opposite side thereof. The floor elements are supported on basement walls or basement beams, which determine a basement space into which the lower end of the slots debouch. This basement space can be connected to an over- or under¬ pressure source of gasses, in particular air. In the first case air is sucked from the basement space, as a result of which air flows through the slots to the basement space, the latter resulting in air being sucked in from the layer of goods supported on the floor element, which latter air is then replenished with air from above the goods, the goods being repeatedly brought into contact with fresh air as a consequence. In the second case pressurized air is fed to the basement space and is pressed by the overpressure through the slots in order to flow via the interspaces between the goods to the space above the goods. The known floor elements have quite a large supporting surface, interrupted by the outlets of the ventilation slots. In the case of the underpressure system the flow of air through the layer of goods will be substantially directed towards the discrete places of this outlet. In the case of the overpressure system the air will enter the layer of goods at the location of the outlet of the slots. In both cases in the area of the layer of goods which is between the slots the flow of air will remain reduced, to such an extent that anaerobic processes can occur there. Another drawback of the known floor elements is that when a part of the quantity of goods has to be removed, this has to take place by digging off a substantially horizon- tal layer of goods. The reason for this is that it has appeared that if one were to remove the goods in the easiest manner by digging away the desired quantity from the side, whereby a part of the total supporting surface of the storage would become exposed, at any rate the thickness of the layer of goods would display considerable differences, the air flow would take place substantially via the slots which debouch into the uncovered or less covered areas. Because of the absence of goods there, the resistance will be lower than there where the goods are situated. By digging off a horizontal layer this big difference in resistance is prevented, but this has the disadvantage that a relatively large effort has to be made to remove the desired quantity of goods. It is an object of the invention to provide a wall element (a floor or vertical wall element) , with which an im¬ provement is made to the above. For this purpose the invention provides a wall element for a storage space for compost, potatoes, seeds and other products, which have to be in contact with a fluid such as air during storage, as described in claim 1. As a result a flow of fluid is made possible directly below the layer of goods in a direction parallel to the supporting surface, so that in the case of the underpress¬ ure as well as the overpressure system, the contact area between the lower surface of the stored layer of goods and the fluid becomes as large as possible, without the con¬ structive strength of the wall element being noticeably reduced due to saving material. Because the fluid can spread over a larger area the resistance against the fluid flow there is also comparatively low. The resistance which the fluid flow meets with will now be at its highest at the location of the first fluid pass¬ ages, which form the smallest flow cross section in the (whole) flow path. This means that the local flow rate is no longer substantially determined by the layer of goods but by the wall elements themselves, so that the flow rate, as considered over the supporting surface, will be more uniform, that is to say determined to a lesser extent by the degree of loading and the differences therein. Preferably the further, widened fluid flow passages commu¬ nicate with one another in a direction parallel to the supporting surface permitting the pressure to be dis- tributed evenly to a large extent over the above-mentioned contact area. Preferably the further fluid passages divide the suppor¬ ting surface into discrete portions. The further passages are advantageously formed as channels. When a maximum of further fluid passages is desired these channels intersect each other, preferably perpendicularly, and by that they delimit discrete portions of the supporting surface in the form of right angles, for example squares. Preferably the channels have a trapezoidal cross section. This does not only offer advantages for the manufacture of the wall element if the latter is casted with the help of moulds but also offers the advantage that, along with ful¬ filling their distributing function, in an overpressure system the channels also help in the spreading of the fluid in the direction perpendicular to the supporting surface. The first fluid passages widen preferably in the direction away from the supporting surface and are for instance conical. In this way this parts of the stored product which get into the first fluid passages are prevented from being subject to arching and from subsequently clogging the first fluid passage. The dimensions of the first fluid passages, the further fluid flow passages and the supporting surface, as seen absolutely and relatively, will depend on the nature and the dimensions of the product to be stored, as well as those of the supporting surface. When storing sugar beet the dimensions of the further fluid flow passages in the plane of the supporting surface can be larger than when storing onions or seed-potatoes. If seeds have to be stored, loss of material can be avoided by an extra measure, that is by laying a net with a suitable mesh size on the supporting surface. By using the net which forms as it were bridges at the location of the further fluid flow passages, a wall element with fluid openings in the supporting surface, which are larger than the nominal grain diameter of the grain of the stored product, can still be used for that purpose. It is noted that a loadbearing floor for crops is known from the UK patent application 2 132 744, formed by a number of floor elements laid down on a firm base, which floor elements are provided with tubular air ducts extend¬ ing parallel to the base, and with a number of parallel channels extending perpendicular to these air ducts which are located above there, and are formed in the supporting surface. The channels intersect the tubular air ducts so as to form air passage openings there. Moreover, from the UK patent 1 604 969 a floor element is known for storage spaces for crops, which is provided with through, slot-shaped air supply ducts extending perpen¬ dicular to the supporting surface, which debouch into the supporting surface of the floor element via widened upper portions. The invention will now be described in more detail with refernce to a preferred embodiment as shown in the draw¬ ing. Fig. 1 shows a schematic cross section of the floor of a storage space, in which wall elements according to the invention are incorporated; and Fig. 2 shows a top view of a wall element of the floor according to fig. 1. The floor of the storage space shown in fig. 1 is built up of a concrete floor 4, a system of beams 2 arranged thereon and a series of prefabricated wall elements, here floor elements 1, supported on the beams 2. The space between the floor elements 1 and the concrete floor 4, being laterally delimited by the beams 2 , forms a basement space 3, through which, in this case, air can be dis- charged, in the case of an underpressure system, or air can be supplied, in the case of an overpressure system, which last system is applicable in this example. On the floor elements 1 a layer of goods 13, such as compost, potatoes, carrots, sugar beet but also seeds, grains and so forth is stored, which require fresh air during stor¬ age. The floor elements 1 have a lower surface 6 and an upper surface 5, which latter surface serving as a supporting surface for the goods. The supporting surface 5 is divided into square surfaces 7, which are delimited by dividing channels 8, 9, which intersect each other perpendicularly and form a network of channels. The channels 8, 9 are trapezoidal and widen upward. At the location of the intersections of the channels 8, 9 in the bottom thereof outlets 11 of frustoconical ventilation passages 10 with circular cross section are provided, which extend from the lower surface 6 through the floor element 1 and thus form an air link between the basement space 3 and the area above the floor element 1. When pressurized air is supplied to the basement space 3 it will escape through the ventilation passages 10 upward in the directions A, exit the ventilation passages 10 at the location of the outlets 11 and will partly flow dir¬ ectly through the layer of goods and partly sidewards through the channels 8, 9 in the directions B (see fig. 2) and finally flow in the direction C into the layer of goods in a place between adjacent outlets 11. Thus, it is accomplished that with a relatively small total flow section of the ventilation passages 10 a large part of the lower boundary surface of the layer of goods is supplied with air. If the goods 13 are fine-grained, such as seeds, it is recommended laying a net 12 over the supporting surface 5 which prevents seeds getting into the channels 8, 9 and/or outlets 11. By way of example the floor element can have the following dimensions. Starting from a storage for onions having a nominal diameter of 4 to 10 cm, the thickness of the floor element, that is the distance between the surfaces 5 and 6, can be 20 cm, with a breadth and length of the floor element of 3 and 2 meters respectively. In this example the depth of the channels 8, 9 can be 2 cm and the largest width of the channels 8, 9 can be 2 cm. Here the discrete supporting surfaces 7 have dimensions of 10 by 10 cm. Finally, in this case the ventilation passages 10 are conical, with the smallest opening at the top, at the location of the outlets 11, having a diameter of 2 cm, and the largest opening in the lower surface 6 having a dia¬ meter of 4 cm. Such a floor element, made of concrete and provided with span or field reinforcement is suitable for being driven on with lorries delivering the goods, for example with a wheel load of 6 tons.

Claims: C L A I M S 1. Wall element for a storage space for compost, potatoes and other products which have to be in contact with a fluid such as air during storage, wherein the wall element has first fluid passages, which debouch into the side of the wall element which faces the products, and wherein the wall element has a supporting surface, which offers sup¬ port to the stored products, wherein the outlets of the first fluid passages are positioned retracted with regard to the supporting surface, wherein, between the outlets of the first fluid passages and the supporting surface, further fluid passages are provided, which are widened relative to the outlets, wherein in a direction parallel to the supporting surface the further, widened fluid flow passages communicate with one another, and wherein the first fliud passages extend transversely through the wall element from the retracted outlet to the opposite side of the wall element. 2. Wall element according to claim 1. wherein the further fluid flow passages define discrete portions of the sup¬ porting surface. 3. Wall element according to claim 1 or 2, wherein the further fluid flow passages are channels which are open towards the supporting surface. 4. Wall element according to claim 3 , wherein the channels intersect each other, preferably perpendicularly, and delimit support surfaces therebetween in the form of right angles, preferably squares. 5. Wall element according to conclusie 3 or 4 , wherein the channels have a bottom, and the outlets of the first fluid passages are situated in the channel bottom. 6. Wall element according to claims 3, 4 or 5, wherein the channels have a trapezoidal cross-section, which widens towards the supporting surface. 7. Wall element according to any one of the preceding claims, wherein the first fluid passages widen in the direction away from the outlet. 8. Wall element according to claim 7. wherein the first fluid passages are conical, preferably with an circular cross section. 9. Wall element according to anyone of the preceding clai¬ ms, wherein the wall element is made of concrete and is preferably provided with a reinforcement in order that the wall element can be walked and riden on. 10. Assembly comprising a wall element according to any one of the preceding claims, and a net which is supported on the supporting surface and which forms a further sup¬ porting face at the location of the further fluid flow passages, which further support surface is spaced from the openings of the first fluid passages in a direction per¬ pendicular to the support surface.

Inventors: VAN DEN BOSCH GERRIT, VAN DEN BOSCH, GERRIT
Applicants: BOSCH GERRIT VAN DEN, VAN DEN BOSCH, GERRIT
Application year: 1994
Main classification: A01F25
IPC codes: A01F25, F26B25